The present invention relates to an improved electrical connector useful for connecting batteries to cable wire, and in particular, for connecting the battery posts of storage batteries to vehicles.
Electrical connectors that are used to connect the battery posts of storage batteries to the electrical systems of vehicles have demanding corrosion-resistance and vibration-withstanding requirements. The corrosion-resistance requirements arise from the highly corrosive galvanic coupling environment of storage batteries. Storage batteries typically contain corrosive acids that vaporize and condense on the battery posts and electrical junction points of the electrical connector. The hygroscopic acids and byproducts thereof, absorb moisture from the ambient environment to form highly corrosive chemical species which rapidly corrode the electrical connector, cable wire, and battery posts. Such corrosion is further aggravated by the galvanic coupling that occurs between the battery post, connector, and cable wire, due to the electrical charge flowing through the metal connector components. The electrical connectors are also subject to high levels of vibrational stresses during operation of the vehicles. The vibrational stresses can cause the electrical connectors to release the cable wire or loosen about the battery post, resulting in shorting and sparking of the electrical junction and malfunctioning of the vehicle.
Conventional electrical connectors that are fabricated using numerous components provide limited corrosion resistance and often fail in high vibration environments. For example, FIGS. 1a-1c show a conventional electrical connector 10 that comprises (i) a battery post connector 11 that compression fits around the battery post, and (ii) a side-mounted cable connector 12 that is clamped on an exposed cable wire. The battery post connector 11 is compression fitted about the battery post by tightening a nut and bolt assembly 13 extending through the free ends 14a, 14b of the battery post connector. The side-mounted cable connector 12 compresses the exposed cable wire between a base 15 and a clamping plate 16 by tightening of the nut and bolt assemblies 17a, 17b therethrough, as shown in FIG. 1c.
The side-mounted cable connector 12 of the electrical connector 10 has several operational disadvantages. First, the side-mounted cable connector 12 lengthens the overall size of the electrical connector 10 often rendering the connector unsuitable for use in small engine compartments of compact cars and motorcycles. In most storage batteries, the battery posts are located at the perimeter of the battery, causing the attached electrical connector 10 to extend outwardly from the battery (as shown in FIG. 1a), and resulting in electrical contact and shorting of the connector 10 with the electrically conductive portions of the vehicle. Also, the relatively large sized and outwardly extending connector 10 can limit access to other components within the engine compartment of the vehicle, and require that the connector 10 be disconnected during service or repair of the vehicle. Furthermore, the side-mounted connector 12 is also often structurally weak at the joint 18 with the battery post connector 11, and can break-off at the joint during fabrication or during mounting of the electrical connector 10.
Another problem with conventional electrical connectors 10 results from the multiple nut and bolt assemblies 13, 17a, 17b that are used to tighten the connector around the battery post, and to compress the cable wire in the side-mounted cable connector 12. The numerous nut and bolt assemblies increases the chances of loosening of one or more of the assemblies during operation of the vehicle due to the high vibrational stresses placed on the connector. This results in disconnection or sparking at the battery post and cable wire junctions. Also, the large number of separate components of the connectors reduces the corrosion-resistance of the connector, due in part to the large surface area of the components, and in part to the sharp corners and edges of the components which can rapidly corrode in galvanic coupling environments because of the higher inherent surface energy of such features.
Thus, it is desirable to have an electrical connector with a reduced number of components to minimize the corrosion and vibration-induced failure of the connector, during operation of the vehicle. It is even more desirable to have an electrical connector that comprises a single integral assembly of components. It is further desirable to have an electrical connector that occupies a small cross-sectional area for use in small engine compartments.